Apache JSPWiki: Authentication Bypass by Spoofing
CVE-2026-28812 is a critical-severity authentication bypass by spoofing vulnerability in Apache JSPWiki from Apache, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2.12.4 as the first without the flaw, so updating Apache JSPWiki to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.69% chance of exploitation within 30 days, higher than 53% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Apache JSPWiki to 2.12.4 or a later version.
- Update Jspwiki to 2.12.4 or a later version.
- Read the advisory on lists.apache.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache JSPWiki | before 2.12.4 | 2.12.4 |
| Apache | Jspwiki | before 2.12.4 | 2.12.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
UserManager lack of checks allows impersonation in Apache JSPWiki up to 2.12.3 which may allow attackers to escalate privileges. Users are recommended to upgrade to version 2.12.4 or newer which fixes this issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authentication Bypass by Spoofing
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
More Authentication Bypass by Spoofing vulnerabilities (CWE-290)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- openwall.com/lists/oss-security/2026/07/30/15Mailing List, Third Party Advisory
Other vulnerabilities in Apache JSPWiki
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
Recent Authentication Bypass by Spoofing vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.2 High severity
- 7.5 High severity
- 9.1 Critical severity
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